Currently known minimally invasive procedures for diagnosis and treatment of medical conditions use shapeable instruments, such as steerable devices, flexible catheters or more rigid arms or shafts, to approach and address various tissue structures within the body. For various reasons, it is highly valuable to be able to determine the 3-dimensional spatial position of portions of such shapeable instruments relative to other structures, such as the operating table, other instruments, or pertinent anatomical tissue structures. Such information can be used for a variety of reasons, including, but not limited to: improve device control; to improve mapping of the region; to adapt control system parameters (whether kinematic and/or solid mechanic parameters); to estimate, plan and/or control reaction forces of the device upon the anatomy; and/or to even monitor the system characteristics for determination of mechanical problems. Alternatively, or in combination, shape information can be useful to simply visualize the tool with respect to the anatomy or other regions whether real or virtual.
In many conventional systems, the catheter (or other shapeable instrument) is controlled in an open-loop manner, as described in U.S. patent Ser. No. 12/822,876, the contents of which are incorporated by reference in its entirety. However, at times the assumed motion of the catheter does not match the actual motion of the catheter. One such reason for this issue is the presence of unanticipated or unmodeled constraints imposed by the patient's anatomy.
Thus to perform certain desired applications, such as, for example, instinctive driving, shape feedback, and driving in a fluoroscopy view or a model, there exists a need for tool sensors to be properly registered to the patient in real time. Moreover, there remains a need to apply the information gained by spatial information or shape and applying this information to produce improved device control or improved modeling when directing a robotic or similar device. There also remains a need to apply such controls to medical procedures and equipment.